1. Field of the Invention
The present relates to a multimedia messaging service (MMS) system and the service method thereof, in particular, to an MMS system and the service method thereof in which integrates mobility management mechanisms of GSM/GPRS/UMTS mobile network and wideband transmission services of wireless local area network (WLAN), and enables user authentication and location management.
2. Description of Related Art
GSM Short Messaging Service (SMS) has now become the most successful wireless data service ever since 1992. GSM short message service allows only mobile users to transfer and receive text short messages of no more than 160 characters. Accordingly, in order to create more revenue from current GSM networks, mobile phone operators promoted Enhanced Messaging Service (EMS), offering user features of enhanced messaging services for transferring and receiving combinations of texts, simple pictures and music, which can be considered as extensions of GSM short message service; that is, each enhanced short message is treated as a series of GSM short messages. Succeeding to the enhanced messaging service, era of Multimedia Messaging Service (MMS) emerges.
Multimedia messaging service provides message transmissions among mobile devices, as well as between applications and mobile devices, offering integral and various contents, including: texts, pictures, audio and video. Multimedia messaging system can join different networks and networks of different types, and integrate existing short messaging systems, forming the Multimedia Messaging Service Environment (MMSE). Now refer to FIG. 1, which illustrates a diagram of a multimedia messaging service system environment. As shown in FIG. 1, in a multimedia messaging service system environment 1, a Multimedia Messaging Service Server (MMS Server) 10 joins a GSM/GPRS/UMTS mobile network 12 and Internet 14, and integrates the short message service elements into these networks to provide user with services of multimedia messaging transmission. The GSM/GPRS/UMTS mobile network 12 comprises second generation (2G) mobile networks (e.g. GSM, GPRS) and third generation (3G) mobile networks (e.g. UMTS). In brief, the multimedia messaging service server 10 is responsible for handling multimedia messages, and takes advantage of data transmission services provided in various networks to send content-rich multimedia messaging. In addition, the multimedia messaging service server 10 also offers convergent functions between the Multimedia Messaging Service User Agent (MMS User Agent) 18 and the External Server 16, such that various servers in different networks can be integrated. The multimedia messaging service server agent 18 provides multimedia message service user with functions for viewing, editing and processing multimedia messaging. The external server 16 is coupled to servers in various types of networks. For example, in the multimedia messaging service environment 1, the GSM/GPRS mobile stations or UMTS user equipments consisting of the multimedia messaging service server agent 18 can utilize the mobile network services provided by the GSM/GPRS/UMTS mobile network 12, submitting and retrieving multimedia messages via the multimedia messaging service server 10. Besides, the GSM/GPRS mobile stations or UMTS user equipments can also receive emails from the external server 16 (e.g. email servers), or submit multimedia messaging to users of the external server 16, through the multimedia messaging service server 10.
The GSM/GPRS/UMTS mobile network 12 can actually provide data transmission rates of only 9.6/50/300 kbps, resulting in the contents which short message service can provide are not only lack of diversity, but expensive in service charge. Insufficiency of wireless bandwidth has now become one tough issue with which the GSM/GPRS/UMTS mobile network 12 is confronted for providing multimedia messaging service. Thus, in case the problem of bandwidth insufficiency can be solved, multimedia messaging service will facilitate to create a win-win result for both users and network service vendors. Among various wireless technologies currently used, wireless local are network (WLAN) is the only one which allows for wireless broadband transmission service, but, however, WLAN may not provide a good mobility management mechanism as the GSM/GPRS/UMTS mobile network 12 does. Hence, it is possible to provide mobile users with content-rich multimedia messaging service, supposing the mobility management mechanism of the GSM/GPRS/UMTS mobile network 12 and the broadband transmission service of WLAN can be well integrated.
Still, current mobile application services are dominated by the system operators of the GSM/GPRS/UMTS mobile network 12 to an extremely high extent; thus, if only integrating the mobility management mechanism of the GSM/GPRS/UMTS mobile network 12 and the broadband transmission service of WLAN, though being effective for multimedia messaging service provision, the business model, user authentication and user location management thereof will surely become under the control of the operators of the GSM/GPRS/UMTS mobile network 12, which is unfavorable for other competitors to participate, furthermore adversely effecting the promotion and application of multimedia messaging service as well. Therefore, for the purpose of providing multimedia messaging service and enhancing the promotion thereof as well as application, in addition to integrating the mobility management mechanism of the GSM/GPRS/UMTS mobile network 12 and the broadband transmission service of WLAN, it is required to design a set of user authentication and location management mechanism completely independent of the GSM/GPRS/UMTS mobile network 12.